How do I

DefenderBLACK · Posted: Sun Sep 14, 2003 8:04 am Post subject: How do I

Wanting to convert my six digit OS map grid ref's into lat/long so I can enter them in to TT2 using the program from TT website for POI.

Is their a program that converts these grid refs or do I have to visit each point on the map and take my own reading

Thanks,

Paul.

DavidW · Posted: Sun Sep 14, 2003 8:04 am Post subject: How do I

There is an algorithmic way to convert between OSGB36 and WGS84. There's a pretty much surveying grade convertor available at http://www.gps.gov.uk (you need to register for a password - it's free), with just one drawback - you need to decode the grid letters (like TL) into the hundreds of thousand figures for eastings and northings.

For example, TL021435 needs entering as

Eastings: 502100

Northings: 243500

(enter any height you like, including 0m - it's not going to make any difference for what you're doing - if height comes into the conversion, it's not to any appreciable extent, and by far the biggest error here is your grid references only being six figure and therefore only accurate to the nearest 100m)

If you have any printed OS maps to hand, you can find the hundreds of thousands figures for that sheet in the corners. Alternatively, look at the picture here and count from the bottom left (the first square is 0, the second 1 and so on).

Does that get you going? You may find the spreadsheet available from the gps.gov.uk web site easier, though there's also a bulk conversion facility.

IIRC the format for POI files is decimal degrees - use of POIEdit is probably the easiest way to enter the POIs.

David

DefenderBLACK · Posted: Sun Sep 14, 2003 8:04 am Post subject: How do I

Cheers, should have known it wouldnt be easy, thanks for the tips, off now to try the downloads from poi and gps.gov.

Thanks again,

Paul

nicknick · Regular Visitor Joined: 03/02/2003 17:18:53 Posts: 154

Or for one at a time conversions try www.streetmap.co.uk or you could try

waypoint workbench which I find is a useful conversion tool

_________________
Nick

Privateer · Posted: Sun Sep 14, 2003 8:04 am Post subject: How do I

Paul,

If you use WinOV2 (download from here) you can create a .ASC file (use another POI as an example) and then use WinOV2 to convert it to .OV2 format.

The latest version of WinOV2 allows you to input UK Ordnance Survey references with the two letter identifier, and it will convert to Long/Lat with the WGS84 Datum.

Regards,
_________________
Robert.
iPhone 6s Plus, iOS 14.0.1: iOS CamerAlert v2.0.7
TomTom GO Mobile iOS 2.3.1; TomTom (UK & ROI and Europe) iOS apps v1.29
Garmin Camper 770 LMT-D

	PocketGPS
	Web